A printer is provided with a print unit having a print head that prints predetermined information on a print medium, and a platen roller provided to face the print bead by interposing the print medium. In addition, predetermined information is printed on the print medium by nipping a print medium between the print head and the rotating platen roller and conveying the print medium.
When the print medium is loaded on the printer, a relative position of the print medium to the print unit is detected by detecting a position mark or a gap between neighboring labels formed on the print medium by using a sensor arranged in the upstream side of the print unit.
It is noted that a sheet conveying operation of a printer has been discussed in some literatures such as JP 2005-314047 A.